Latching mechanism

ABSTRACT

A LATCH FOR LATCHING DOCKING RINGS ON A SPACE VEHICLE, FOR EXAMPLE. IT INCLUDES A LATCHING HOOK CONNECTED TO A STORED ENERGY POWER PACKAGE, SUCH AS A SPRING, AND A COCKING HANDLE WHICH SIMULTANEOUSLY UNLATCHES THE HOOK AND STORES ENERGY IN THE POWER PACKAGE. IT ALSO INCLUDES TRIGGERING MEANS TO PROPERLY POSITION THE HOOK AND TO RETAIN THE HOOK IN THE COCKED POSITION UNTIL RELEASED AT THE DESIRED TIME.

Feb. 16, 1971 T. o. PAINE 3,564,564

ADMINISTRATOR OF THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATIQNLATCHING MECHANISM Filed NOV. 21., 1969 'a Sheets-She et 1 (@606 C.C060? Zea Z. f-Ffloaeu IINVENTORJ BY 6. dyH/ZW.

ATTOIP/VEVJ Feb. 16, 1971 T. o. PAINE 3,564,564

ADMINISTRATOR OF THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATIONLATCHING MECHANISM Filed Nov. 21, 1969 8 Sheets-Sheet 2 o (/5606 (T(ab/'0 Zea L 3600 91 79 INVEN'I'ORS BY 7 q f T. O. PAINE Feb. 16, 19713,564,564

ADMINISTRATOR OF THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATIONLATCHING MECHANISM 8 Sheets-Sheet 8 Filed Nov. 21, 1969 Zea Z. Riva en:

INVENTORJ Feb. 16, 1971 1-. o. PAINE 3,564,564

ADMINISTRATOR OF THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATION 4LATCHING MECHANISM Filed Nov. 21, 1969 8 Sheets-Sheet 4.

I I I) I' T. O. PAINE Feb. 16, 1971 ADMINISTRATOR OF THE NATIONALAERONAUTICS AND SPACE ADMINISTRATION LATCHING MECHANISM Filed Nov. 21,1969 8 Sheets-Sheet 5 c/Zrcozfi C. (ad/'0 Zea A Rhea em INVENTORJ' BY IQ L 5 6 gum Feb. 16,1971

T. o. PAINE 3,564,564

ADMINISTRATOR OF THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATIONLATCHING MECHANISM Filed Nov. 21, 1969 8 Sheets-Sheet 6 c/kcazf C (05/77Zea L #60049:

INVENTORJ 3,564,564 NAu'ncs T. OhPAINE Feb. 16, 1971 ADMINISTRATOR OFTHENATIONAL AERO AND SPACE ADMINISTRATION LATCHING MECHANISM 8 Sheets-Sheet'7 Filed Nov. 21, 1969 l N VEN UR.

QL g Ba (/5606- C (ob/77 Zea Z. Pfioaeu ATTOF/VEJQI Feb. 16, 1971 H I T.o. PAINE ADMINiSTRATOR OF THE NATIONAL AERONAUTICS AND SPACEADMINISTRATION LATCHING MECHANISM 8 Sheets-Sheet 8 Filed Nov. 21, 1969 n.0... E 1 N 3 ,a/wfm W 0 5 n V Q A m v a 5L mm 9 i J4 Y W Y B m 6 a z 3W, W Z2; f Z/ wg /w a 275 o 5 o o United States Patent O 3,564,564LATCHING MECHANISM T. O. Paine, Administrator of the NationalAeronautics and Space Administration with respect to an invention ofJacob C. Cobin, Los Angeles, and Leo L. Rhodes,

Palos Verdes Estates, Calif.

Filed Nov. 21, 1969, Ser. No. 878,731 Int. Cl. A44b 21/00 US. Cl. 24-26317 Claims ABSTRACT OF THE DISCLOSURE A latch for latching docking ringson a space vehicle, for example. It includes a latching hook connectedto a stored energy power package, such as a spring, and a cocking handlewhich simultaneously unlatches the hook and stores energy in the powerpackage. It also includes triggering means to properly position the hookand to retain the hook in the cocked position until released at thedesired time.

ORIGIN OF THE INVENTION The invention described herein was made in theperformance of work under an NASA contract and is subject to theprovisions of Section 305 of the National Aeronautics and Space Act of1958, Public Law 85568 (72 Stat. 435; 42 U.S.C. 2457).

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to a novel latoh. More particularly, it relates to an automaticlatch for securely clamping together two objects.

Description of the prior art Prior art latches used in connection withthe latching together of docking rings of the command module and thelunar module of the Apollo spacecraft in the space environment providedonly semi-automatic latching, which latches required subsequent manualoperation to obtain the required hook preload on the lunar moduledocking ring, for example. Also, the prior art latches did not provideadequate hook travel to allow for lunar module ring distortion. US. Pat.No. 3,346,929 is generally illustrative of the prior art over which thepresent invention is an improvement.

SUMMARY OF THE INVENTION It is therefore an object of this invention toprovide an improved latch which provides full automatic actuation andpreloading at the initial docking with sufiicient hook travel to allowfor lunar module ring distortion and adverse tolerance accumulation.

It is also an object of this invention to provide a latch havingmultiple stage cocking and automatic drive pawl disconnect means, withthe mechanical arrangement such that there is provided means for lockingin stored energy in a power device with more than one cocking stroke ofan operating handle to reduce the operating force and to additionallyautomatically disconnect the driving pawl from the ratchet to removeinterference during power release actuation.

It is also an object of this invention to provide automatic no-backratchet disconnect means wherein the mechanical arrangement is such thatthere is provided means of restraining a shaft against reversiblerotation and automatically removing the no-back restraint to allowreverse rotation.

It is a further object of this invention to provide a latch havingautomatic gear shift linkage connecting a ice stored energy power source(spring bungee) to an operator shaft, which automatically shifts duringshaft rotation to provide maximum output torque through the effectiverange of operation and minimum output torque through the ineffectualportion of the stroke and wherein the gear shift operation isaccomplished by means of a single unstable link.

It is another object of this invention to provide a latch havingautomatic reset triggering means including means for holding a storedenergy device in a cocked position, releasing this energy device whentriggered for actuation, and automatically resetting for recocking.

Briefly stated, the invention comprises a crankshaft having a pinportion eccentric with the shaft. A latch member in the form of a hookis mounted for rotation upon the pin portion, with the crankshaftarranged to move the hook to the latched position during rotation of theshaft in a first direction and to move the hook to the unlatchedposition during rotation of the shaft in the opposite direction. It alsoincludes a power package, such as a spring bungee, operably connectedwith the shaft for exerting a torque force to rotate the shaft in thefirst direction. Means are also provided for rotating the shaft in theopposite direction to thereby move the hook to the unlatched positionand simultaneously store energy in the spring. Trigger means areprovided for holding the spring with the stored energy and in theunlatched or cocked position releasing the spring when triggered foractuation to move the hook to the latched position and for automaticallyresetting for recocking.

Certain embodiments of the invention may also include automatic gearshift linkage means connecting the power spring bungee to the shaftwhich automatically shifts during shaft rotation to provide maximumoutput torque through the effective range of operation and minimumoutput torque through the ineffectual portion of the stroke. It may alsoinclude a no-back pawl which while restraining the shaft againstreversible rotation is arranged for automatic disengagement, whichdisengagement is etfected during rotation of the shaft in the oppositedirection. The sequential triggering arrangement provides proper hookposition before energy is released. Also included is a mechanicalarrangement which provides means of locking in stored energy in a powerdevice with more than one cocking stroke of an operating handle toreduce the operating force and automatically disconnects the drivingpawl from the ratchet to remove interference during power releaseoperation.

While the specific embodiment is directed to an automatic latch used tosecure the command module to the lunar module of the Apollo spacecraft,it may be used for automttic coupling of remote controlled equipmentsuch as Telestar satellite power package additions, space stationassembly, nuclear power operations, deep ocean equipment construction,sea rescue or salvage operations, etc. Moreover, some of the novelfeatures may be used singly or in various combinations.

BRIEF DESCRIPTION OF THE DRAWINGS Reference to the drawings will furtherexplain the in vention wherein like numerals refer to like parts and inwhich:

FIG. 1 is a perspective view of the end of the command module dockingring of a space vehicle, showing twelve latches of this inventionmounted thereon in pairs.

FIG. 2 is a side view of the latch assembly having the docking rings ofthe command module and lunar module in dotted line.

FIG. 3 is a front elevation view of the latch with a portion of thecocking handle partially broken away.

FIG. 4 is a view similar to FIG. 3 with the cocking handle removed and aportion of the latching hook removed.

FIG. is an isometric and partially exploded view of the latch assembly.

FIG. 5A is an enlarged portion of the hook and hook pawl shown in FIG.5, but rotated 90.

FIGS. 6, 7 and 8 are sectional views taken generally along lines 2A2A ofFIG. 3, and show the operation of the automatic gear shift linkage insequence.

FIGS. 914 are generally fragmentary sectional views taken generallyalong lines 4-4 of FIG. 3 and showing the multiple stage cocking andautomatic drive pawl disconnect mechanism in sequence.

FIGS. -17 are fragmentary sectional views generally taken along lines5-5 of FIG. 3 and showing the automatic no-back ratchet disengagement insequence.

FIGS. l820 are sectional views taken generally along lines 33 of FIG. 3showing the automatic reset triggering mechanism in sequence.

FIG. 21 is generally a view taken generally along line 21-21 of FIG. 18.

FIG. 22 is an isometric view of the main housing of the inventionshowing most of the moving parts removed therefrom.

FIG. 23 is generally a horizontal sectional view taken through the maincrankshaft.

FIG. 24 is a sectional view similar to FIG. 9, but along a line nearerthe end of the latch.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, the endsection of docking ring 11 of the command module of the Apollospacecraft has twelve latches designated by the numeral 12 mounted inpairs about the circumference thereof. Each of the latches 12 has ahandle 13 which is arranged for pivoting downward and radially inwardly,the same being shown in FIG. 1 in the actuated position. A spring bungee14 is mounted therebeside with a latch hook 15 shown in the actuatedposition and facing generally outwardly and adapted for engagement witha mating docking ring on the lunar module (not shown). Docking ring 11has a pair of annular seals 16 to effect sealing between the member tobe latched by hooks 15, to provide a seal between docking ring 11 andlunar module docking ring 17, as shown in dotted line in FIG. 2, forexample. The latch mechanism of this invention is generally included ina housing designated by the numeral 18 which is arranged for attachingby any convenient means, such as threaded fasteners, to docking ring 11.

Referring now to the drawings generally and FIG. 5 particularly, handle13 is pivotally mounted by a pin 20 passing through pin holes 96-98 ofhousing 18, for rotation through an angle of approximately 100. Handle13 is arranged for return to the original starting position, as shown indotted form, by means of a handle return bungee assembly 21 which isconnected to a rod 22 which in turn is connected to bungee support 23 atan angle, which support is shown in FIG. 3 and which is mounted on pin20, to thereby provide a biasing force to urge handle 13 to return tothe starting position. The upper end of bungee assembly 21 is connectedto transversely extending pin 26 on the back side of handle 13, as seenin FIG. 3, and on which is also mounted a pivotal handle latch plate 24which, when depressed toward handle 13 and against the bias of spring19, causes handle latch 25 connected therewith (as shown in FIG. 5) torotate generally upwardly.

Handle 13 also has pivotally connected thereto a strap 27, the upper endof which is provided with an elongated slot 28 in which is received pin29 connected to the back side of hook, 15 such that downward rotation ofhandle 13 retracts hook 15 after a distance of free travel provided byslot 28. Hook 15 is also urged to the latched or upward position bymeans of spring 31 mounted on spring rod 32, the lower end of which ispivotally mounted on pin 20. The upper end of spring 31 is similarlysupported by rod 4 33 pivotally connected to hook 15, as seen in FIGS. 3and 18.

Handle 13 also has pivotally attached thereto a driving link 34 mountedon pivot pin 38, with the other end of link 34 being connected todriving crank 35 which is mounted for rotation on crankshaft 37.Crankshaft 37 is provided with an intermediate pin portion 36 that iseccentric with respect to crankshaft 37, as best seen in FIGS. 5 and 23,and during rotation of crankshaft 37 the axis of pin portion 36 iscaused to move through an are laterally spaced from the axis of rotationof crankshaft 37.

Crank 35 has mounted on the side thereof connecting means in the form ofdriving pawl 39 which is pivotally connected thereto and is biaseddownwardly by spring 40 the upper end of which is also pinned to crank35. Pawl 39 is arranged to engage the first tooth 41 and the secondtooth 42 of a ratchet 43 which is mounted for rotation on crankshaft 37.Ratchet 43 also has a row of smaler teeth 44 and first and seconddetents designated by the numerals 45 and 46 respectively. Teeth 44 arearranged to he engaged by no-back pawls 47, shown in FIG. 4, theoperation of which will be explained in further detail hereinafter.Ratchet 43 is also provided with an auxiliary release notch 57 forwardof detent 45 and a circumferential slot 48.

Detents 45 and 46 are arranged to be sequentially engaged by roller 91mounted in the lower leading edge of power bungee release bell crank 49which is mounted for rotation on a pin (not shown) mounted in housing18, and with the upper arm thereof connected to a toggle linkage 50, theopposite end of which is pivotally connected to another bell crank 51which is mounted on pin 52 and has an arm 53 which is biased upwardly byspring 54. Pin 52 is mounted for rotation in housing 18 and has bellcrank 51 splined thereto on one end and power bungee release arm 55splined to the other end. Arm 55 is arranged for contact by Allen-setscrew 56 on the forward side of hook 15. Hence, when arm 55 is contactedby set screw 56, the toggle linkage arrangement is such that the forwardlower arm of bell crank 49 is pivoted upwardly from en gagement withdetent 45 or detent 46.

In the retracted position, hook 15 has a travel of approximately 16 asshown in FIG. 5. Hook 15 is also arranged to be retained in theretracted position by hook pawl 58 which engages lug 59 connected withhook 15 as shown in FIG. 5A. Referring now to the upper right-handcorner of FIG. 5 and FIGS. 18-2l, a portion of the trigger means of theinvention will now be described. It includes a trigger 61 having aforward end which is arranged for contact by lunar module docking ring17, as shown in FIG. 2, and is pivoted on pin 62 and has a rearward hookportion 63, which is arranged for engagement by handle latch 25connected to handle 13. Trigger 61 is in the form of a bell crankmounted on pin 62 and has a rearwardly extending arm 64 which isarranged for biasing trigger 61 upwardly as shown in FIG. 5. When theforward end of trigger 61 is depressed, it lifts upwardly on arms 64,thereby drawing upwardly hook release rod assembly 67 which is pivotallyattached thereto.

Trigger rod assembly 67 also has a manual release lever 68 which will beexplained in greater detail hereinafter. The trigger means also includesa microswitch 69 which is arranged to provide an electrical output whenthe same is contacted by switch bell crank 70, which is arranged to bedepressed into contact with switch 69 by contact with an Allen-set screw(not shown) in the forward or leading edge of hook 15, when hook 15moves to the closed position. A cam lever 71 is attached to hell crank70 and serves a dual purpose. Its primary function is a cam arranged inrelation with the aforesaid Allen-set screw such that three separatemotions are sensed before actuation of switch 69; (l) safe indication oncrews display panel is indicated when hook 15 is in position over lunarmodule ring. (2) hook 15 must be drawn down to indicate preload, and (3)trigger 61 must be in down position, indicating lunar module ring indocked position (to eliminate the possibility of a false safe indicationshould a latch actuate prematurely). The second function of cam lever 71is to act as a spring-loaded override to protect micro-switch 69 fromoverload by providing additional over-travel.

Referring now to the right side of FIG. 5, biasing means are shown forrotating crankshaft 37 and to store energy, which means are in the formof spring bungee 14 which is arranged for attachment to housing 18 asshown in FIG. 2 by integral trunnion shafts 71 on bungee 14 and housingclip 72. The automati shifting means by which bungee 14 is connected torotate cam crankshaft 37 will be explained hereinafter.

It is to be understood that the various parts shown in FIG. 5 arearranged for mounting and operation in housing 18, which is best shownin FIG. 22. For example, crankshaft 37 shown in FIG. 23 is arranged tobe received in the annular openings 114117 shown provided in theupstanding webbs 126129 of housing 18, with appropriate bearings beingprovided.

AUTOMATIC GEAR SHIFT LINKAGE Referring now to FIGS. 6, 7 and 8, detailsand operations of the automatic gear shift and linkage will now beexplained in greater detail. In FIG. 6, hook 15 is shown in the latchedposition engaging lunar module docking ring 17 which is held againstcommand module docking ring 11. Spring bungee 14 is in the form of acylinder having a piston 74 mounted for movement therein and is biasedupwardly by a pair of springs 75 and 76 and is connected to rod 77 formovement downwardly as shown. The lower end of rod 77 is connected toone end of an automatic gear shift linkage in the form of an unstableshifting lever link 79 by pin 80. The other end of link 79 is pivotallyconnected by pin 81 to an enlarged portion 83 of crankshaft 37 forrotation therewith. The center of rotation of enlarged portion 83 andcrankshaft-37 is designated by the numeral 84. The axis of rotation ofhook 15 is shown by the numeral 85. Enlarged portion 83 of crankshaft 37is provided with a hollowed out portion forming stops 87 and 88 whichare arranged to engage generally downwardly extending lug 89 attached tolink 79, with the limit of movement of link 79 being controlled by stops87 and 88.

FIG. 6 shows the actuated position of hook 15 with springs 75 and 76exerting an upward bias on piston 74 which draws rod 77 upwardly whichin turn causes enlarged portion 83 of shaft 37 to have a torque forceapplied thereto in a first or clockwise direction as shown in FIG. 6 andwith a draw down force being applied to hook 15.

FIG. 7 shows hook 15 in the mid-cocked position with shifting lever link79 in the on-center shifting position and piston 74 being drawndownwardly thereby to provide stored energy in spring 75 and 76.

FIG. 8 shows the full cocked position of hook 15 with shifting link 79in the over-center shifted position and lug 89 contacting stop 87. It isto be understood that springs 75 and 76 may be preloaded to provide thedesired pull down force on hook 15, to thereby provide a continuousclockwise torque on shaft 37 as viewed in FIGS. 6, 7 and 8.

In the FIG. 6 position, shifting lever link 79 is held in its highmechanically advantaged position by spring bungee 14 force. As shaft 37is rotated counterclockwise, shifting lever link 79 position relative toshaft 37 is maintained until the center of pin 80 passes over the centerof line of action of spring bungee 14 as shown in FIG. 7, at which pointshifting lever link 79 pivots about pin 81 until lug 89 engages stop 87.This new position is maintained as the counterclockwise rotation of theshaft 37 is continued to the fully cocked position. Thus, the maximumstored energy is provided by the minimum input force. When shaft 37 isreleased from the cocked position, as will be explained hereinafter, thestored energy in bungee 14 rotates enlarged portion 83 and shaft 37clockwise as shown in FIGS. 6-8. The pull down force of hook 15 isminimum through the ineffectual portion of its" stroke and automaticallyshifts to provide the maximum output at the full down position.

Thus, this means of connecting the bungee 14 to the operating shaft 37through the gear shift linkage described provides the capacity ofconserving most of the stored energy in bungee 14 through theineffectual overtravel portion of the stroke for distribution throughthe remaining effective stroke. This offers a minimum size power packagewith a minimum input operating force and a maximum hook draw down forcethrough the required range. For purposes of convenience, shifting leverlink 79 may sometimes be referred to herein as an unstable link.

MULTIPLE STAGE COCKING AND AUTOMATIC DRIVE PAWL DISCONNECTION MECHANISMReferring now to FIGS. 914 and 24, the operation of the multiple stagecocking and automatic drive pawl disconnect mechanism will be discussed.This portion of the device provides means for locking in stored energyin a power device with more than one cocking stroke of operating handle13 to reduce the operating force and automatically disconnecting thedriving pawl 39 from ratchet 43 to remove interference during powerrelease actuation of hook 15. The operating force is reduced byutilizing more than one operating stroke of handle 13 and thearrangement is such that no separate action is required to disengagedriving pawl 39 prior to actuation of hook 15.

FIGS. 9 and 24 show the apparatus in the actuated position. Shaft 37 hasratchet 43 splined thereto. Ratchet 43 is spring loaded by operation ofbungee 14 to provide counterclockwise bias thereto as shown in FIGS.9-14 and 24. Handle 13 is spring loaded by operation of bungee assembly21, previously explained, to retract to the vertical position shown.Drive pawl 39 is lifted to the raised and non-operating position bycontact with the support surface of housing 18, as shown. Thefunctioning of the mechanism in sequence will now be described. Duringthe first stroke, and at the beginning of that stroke, drive pawl 39moves away from contact with the support surface of housing 18 and iscaused to rotate by spring to engagement with the first tooth 41 onratchet 43. Drive crank 35 which is mounted for rotation on crankshaft37 idles through an angle of approximately 10 until drive pawl 39engages the first tooth 41, as shown in FIG. 10. During the remainder ofthe first stroke, as shown in FIGS. 10 and 11, ratchet 43, pin portion36 and crankshaft 37 are, rotated until the roller 91 mounted in theleading edge of the pawl arm of crank 49 engages first detent of ratchet43. Crankshaft 37, pin portion 36 and ratchet 43 are held in theintermediate cocked position by roller 91 until handle 13 is retractedto the point that driving pawl 39 engages second tooth on ratchet 43, asshown in FIG. 12.

During the second stroke of handle 13, ratchet 43, pin portion 36 andcrankshaft 37 are again rotated in the clockwise direction, as shown inFIGS. 9-14, until roller 91 of crank 49 engages second detent 46 ofratchet 43. The apparatus is now in the fully cocked position. Togglelink is in a safe over-center position, as shown in FIG. 13, and thepower exerted by bungee 14 can be released only by normal operation ofthe power release bell crank 49. The apparatus remains in the fullycocked position while handle 13 is retracted to the vertical position,as shown in FIG 14. Driving pawl 39 is lifted to clear the path ofrotation of ratchet 43 during actuation of hook 15 to the latchedposition.

AUTOMATIC NO-BACK RATCHET DISENGAGEMENT The next portion of the devicewhich will be explained is the portion which provides means ofrestraining shaft 37 against reversible rotation and it includes meansfor automatically removing the no-back restraint to allow reverserotation thereof. This means is best shown in FIGS. 15, 16 and 17. Asstated previously, drive crank 35 is mounted for free rotation oncrankshaft 37 and ratchet 43 is splined to crankshaft 37. FIG. 15 showsthe apparatus in the actuated position with hook 15 latched. No-backpawls 47 are engaged with ratchet teeth 44 which holds crankshaft 37 inthe irreversible position. When handle 13 is pulled, the initial freetravel of drive crank 35 causes the arcuate shaped ramp 92 attached tocrank 35 to engage the cam surface 93 of no-back pawls 47 and lift pawls47 from engagement with ratchet teeth 44, as shown in FIG. 16. Pinportion 36 and shaft 37 are now free for rotation to the cocked positionshown in FIG. 17. It is to be understood that no-back pawls 47 aremounted for rotation on pin 20 and are biased into engagement with teeth44 by spring 95, which spring is compressed during actuation, as shownin FIGS. 16 and 17.

It will thus be observed that no separate action is required todisengage no-back pawls 47 from the ratchet 43. A single pull ofoperating handle 13 removes the noback restraint and rotates shaft 37from its irreversible position.

The purpose of no-back pawls 47 is to make latch 12 capable ofwithstanding externally applied loads in excess of the spring loads, asfor example, bending loads across the command module and lunar moduleinterface during a mid-course direction maneuver. Applied loads on hook15 would tend to cause back-up of the mechanism and the spring bungee inthe absence of no-back pawls 47. Each latch 12, as designed, willwithstand approximately 12,000 pounds of pressure with the first 3,000pounds being opposed by the operation of the spring bungee and the next9,000 by the operation of no-back pawls 47.

AUTOMATIC RESET TRIGGERING MECHANISM Referring now to FIGS. 18, 19, 20and 21, the automatic reset triggering mechanism will be discussed. Thisparticular arrangement provides means for holding a stored energydevice, i.e. bungee 14, in a cocked position and releasing the energythereof when triggered for actuation and automatically resetting andrecocking. It has a self escape means for the reset as will be describedhereinafter.

FIGS. 18 and 21 show hook 15 in the retracted and cocked position.Trigger 61 is biased in a counterclockwise position, as shown in FIG.18, by operation of spring 65 and arm 64 is biased downwardly. Triggerrod assembly 67 is connected at an intermediate point by pin 101 tospring bungee 102 the other end of which is connected by pin 103 tohousing 18, whereby rod assembly 67 is biased generally to the right asshown in FIGS. 18-20. The lower free end of rod assembly 67 supports aroller 105 which is arranged toengage detent 106 of generally diamondshaped cam 107 and for engagement by cam ramp 108 formed in housing 18.

Cam 107 is mounted for pivoting about pin 110 and is biased downwardlyby operation of spring 111. Cam 107 has pivotally connected theretotoggle link 112 which in turn is pivotally connected to toggle crank 113to which is connected hook pawl 58 for rotational movement therewith. InFIG. 18 pawl 58 is shown engaging lug 59 which is attached to hook 15,also as shown in FIG. A. Hook is mounted for rotation about shaft pinportion 36, as shown in FIG. 23.

FIGS. 18 and 21 show the apparatus in the cocked position. The length oftrigger rod assembly 67 is adjusted to trigger at a predeterminedposition. Toggle link 112 is in the over-center position to insurepositive engagement of pawl 58. Hook 15 is released when trigger 61 isde pressed to the release position shown in FIG. 19. Rod roller 105rides up ramp 108 and escapes from cam detent 106 when trigger 61 isfully depressed, and cam 107 is then free to reposition pawl 58 forsubsequent recocking, as shown in FIG. 20. The mechanism now may berecocked even though trigger 61 is depressed (lunar module docked) whenhook 15 is pulled back and pawl 58 is free to reengage under hook lug59.

AUXILIARY RELEASE In the event of excessive lunar module ringdistortion, for example, which would prevent hook 15 from disengagingfrom the lunar module ring during the first stroke of operating handle13, auxiliary release means are provided to cock hook 15. These meansinclude an auxiliary release crank in the form of cam blade 124 mountedfor rotation on pin 20 adjacent pawls 47, as best seen in FIGS. 5 and24. Cam blade 124 has attached to the rearward side thereof an auxiliaryrelease button 123 also shown in FIGS. 3 and 24. The forward end of camblade 124 is arranged to be received in slot 48 of ratchet 43 and to beengaged by the forward portion of ratchet 43 forming first detent 45during rotation of ratchet 43. Cam blade 124 also has attached theretoand supports therebeside auxiliary pawl 125 which is arranged to engageauxiliary release notch 57 which is generally forward of first detent 45of ratchet 43. Auxiliary pawl 125 is normally biased to the non-engagingposition by operation of spring 121, the upper end of which is supportedby upper rod which is pivotally attached to a portion of housing 18 andlower rod 122 which is pivotally connected to a portion of cam blade124. As pressure is applied to button 123, cam blade 124 is moved intorecess 48 causing movement thereof to the overcenter position such thatspring 121 applies pressure to engage auxiliary pawl 125 against ratchet43.

At this point, handle 13 may be rotated downwardly through the firststroke until auxiliary pawl 125 engages auxiliary release notch 57 ofratchet 43. In this position, auxiliary pawl 125 will hold shaft 37 inthe mid-cocked position.

On the second stroke of handle 13, a portion of ratchet 43 will contactthe forward edge of cam blade 124 to cam the same backwardly to theoriginal position where it will be held in that position by theoperation of spring 121. Thus, there is provided safety means forinsuring that hook 15 can be retracted under certain adverse conditionsas described above.

Manual release lever 68, shown in FIG. 5, is splined to a pin, theopposite end of which is connected for rotation with cam 107. Hence, bylifting upwardly on manual release lever 68, cam 107 is rotated upwardlyand the hook 15 is then released. In addition, switch bell crank 70,shown in FIG. 5, is arranged for rotation with bungee 102, and thearrangement is such that bell crank 70 contacts additional contact meanson switch 69 to reflect the various positions of the apparatus as sensedby the position of bungee 102.

OPERATIONAL SEQUENCE The operating sequence of the latch mechanism willnow be described. Hook 15 is moved to the cocked position by two fullstrokes of operating handle 13. Handle 13 is released by depressinglatch plate 24 which disengages handle latch 25. At the beginning of thefirst stroke of handle 13, driving crank 35 idles through an angle of10. This initial travel disengages no-back pawls 47 from ratchet no-backteeth 44 (providing an irreversible clutch) and engages driving pawl 39with ratchet 43. During the remainder of the first stroke, hook 15a islifted approximately one-half of its vertical travel and is rotatedbackwardly approximately 16 for disengagement from lunar module dockingring 17. Hook release pawl 58 engages lug 59 of hook 15. Spring bungee14 is compressed approximately one-half its stroke. Bungee releaseroller 91 on bell crank 49 is engaged in the first detent 45 on ratchet43. In addition, switch bell crank 70 is released from engagement withthe contact of switch 69.

During the second stroke of handle 13, hook is lifted to its fullvertical travel. Bungee 14 is extended to its full stroke. Bungeerelease roller 91 of bell crank 49 is engaged in the second detent onratchet 43. Handle 13 then free wheels upwardly by operation of bungeeassembly 21 to rest against the retracted hook 15. When latch 15 is inthe full cocked position, toggle link 112 (which is operationallyconnected to hook pawl 58) and link (which is connected to power bungeerelease bell crank 49) are both in a safe over-center position and canbe operated only by normal operation.

Latch 12 is actuated to the latching position, either by depressingtrigger 61 or by rotation of manual lever 68, as discussed above. Duringsuch triggering, hook pawl 58 disengages from hook 15. Hook 15 thenrotates to the vertical position over lunar module docking ring 17.Handle 13 follows hook 15 and rotates to the vertical position and liftsdriving pawl 39 from engagement with ratchet 43. Bungee release roller91 in the forward end of bell crank 49 disengages from the second detent45 of ratchet 43. Released energy in bungee 14 rotates shaft 37 and pinportion 36 which draws hook 15 down on lunar module docking ring 17 withapproximately 3,000 pounds of clamping force per latch, and no-backpawls 47 are engaged with ratchet teeth 44. Switch 69 is actuated by thearm of bell crank 70 and handle latch 25 is engaged with hook portion 63of trigger 61.

Further modifications and other embodiments will be apparent to thoseskilled in the art in view of the foregoing description. It is to beunderstood that this invention may be utilized for automaticallycoupling two members other than space vehicles.

What is claimed is:

1. A readily releasable latch assembly for securing a pair of members inassembled relationship including in combination:

a housing attached to one of the members;

a rotatable shaft journalled in said housing, said shaft being in theform of a crankshaft having a pin portion eccentric with the shaftportion;

a stored energy source operably connected with said shaft portion forexerting a torque force to rotate said shaft in a first direction;

an unstable link having one end connected to said shaft portion and theother end operably connected to said stored energy source;

a latch member operably connected with said pin portion for movement tothe latched position during rotation of said shaft in said firstdirection, the latch contacting the other of said members andmaintaining said pair of members in assembled relationship; and,

unlatching means for rotating said shaft counterclockwise to said firstdirection to disengage said latch from contact with said member.

2. The invention as claimed in claim 1 including:

trigger means for retaining said latch member in the unlatched positionand releasing said latch member for movement to the latched position atpredetermined times.

3. The invention as claimed in claim 2 wherein:

said energy sources is in the form of a bungee spring assembly.

4. The invention as claimed in claim 2 wherein said trigger meansincludes:

a pawl arranged to engage and hold said latch member in the retractedpsitin;

and, means for disengaging said pawl at predetermined times.

5. The invention as claimed in claim 4 wherein said disengaging meansincludes:

a cam mounted for pivoted movement through a plane generally normal tosaid shaft;

and, a toggle linkage connecting said pawl and said cam.

6. The invention as claimed in claim 5 including:

a pivoted trigger positioned for contact at the forward end thereof bythe member to be latched by said latch member;

and, a trigger rod pivotally connected to the rearward end of saidtrigger, said rod having a lower free end supporting a cam follower,with said cam follower being arranged to engage and pivot said cam tothe pawl disengaging position when said trigger is actuated.

7. The invention as claimed in claim 6 including:

a spring connected to said cam and arranged to pivot said cam to thepawl engaging position after said cam is released by said cam follower.

8. The invention as claimed in claim 2 including:

means for sensing the latched condition of said latch member andgenerating a signal indicating said latch condition.

9. The invention as claimed in claim 6 wherein said unlatching meansincludes:

a ratchet connected with said shaft for rotation generally therewith;

a drive member mounted for rotation through an are extending generallyabout said shaft;

and, coupling means for coupling said drive member with said ratchetduring rotation of said drive member in said opposite direction.

10. The invention as claimed in claim 9 wherein:

said coupling means includes a drive pawl operably connected with saiddrive member for rotation therewith and arranged to engage said ratchetduring movement of said drive member in said opposite direction and fordisengagement from said ratchet during movement of said drive member insaid first direction to a retracted position.

11. The invention as claimed in claim 9 including:

a power holding pawl arranged to engage said ratchet and hold saidratchet from rotation in said first direction when engaged;

and, means for disengaging said power holding pawl at predeterminedtimes.

12. The invention as claimed in claim 11 including:

a toggle linkage connected to said power holding pawl and arranged tomove to an over center position when said holding pawl is engaged withsaid ratchet in the fully cocked position.

13. The invention as claimed in claim 9 including:

a no-back pawl arranged to engage and hold said ratchet from movement insaid opposite direction when ene s and, means cooperative with saiddrive member for automatically disengaging said no-back pawl duringrotation of said drive member in said opposite direction.

14. In a latch assembly, the combination comprising:

a crankshaft having a pin portion eccentric with the shaft;

a latch mounted for rotation upon said pin portion, with said crankshaftarranged to move said latch to the latched position during rotation ofsaid shaft in a first direction and to move said latch to the unlatchedposition duing rotation of said shaft in the opposite direction;

a spring operably connected with said shaft for exerting a torque forceto rotate said shaft in said first direction;

means for rotating said shaft in said opposite direction to thereby movesaid latch to the unlatched position and simultaneously store energy insaid spring;

and, trigger means for holding said latch in the unlatched position andfor releasing said latch for movement to the latched position atpredetermined times.

15. The invention as claimed in claim 14 including:

an unstable link connected with said shaft at one end and operablyconnected with a spring assembly at the other end.

16. The invention as claimed in claim 14 including:

trigger means for retaining said latch member in the unlatched positionand releasing said latch member for movement to the latched position atpredetermined times.

17. The invention as claimed in claim 14 wherein said means for rotatingsaid shaft includes:

a ratchet connected with said shaft for rotation generally therewith;

a drive member mounted for rotation through an are extending generallyabout said shaft;

and, coupling means for coupling said drive member with said ratchetduring rotation of said drive member in said opposite direction.

References Cited UNITED STATES PATENTS DONALD A. GRIFFIN, PrimaryExaminer

